Polarization Co-Ordination

1. A group of at least two transceiver units in at least one wireless communication system, the transceiver units in the group being arranged for wireless communication with at least one other transceiver unit, where the transceiver units in the group are arranged to transmit signals with polarizations that are essentially parallel to each other when received by at least one transceiver unit for which the transmitted signals constitute interference and the essentially parallel polarizations are orthogonal to a polarization for reception when received by said at least one transceiver unit for which the transmitted signals constitute interference, wherein a) the transceiver units in the group: i) operate in a Time Division Duplex (TDD) mode and not a Frequency Division Duplex (FDD) mode, ii) are arranged to transmit signals during a first set of time intervals and receive signals during a second set of time intervals, the first set of time intervals and the second set of time intervals being separated from each other, and iii) are arranged to transmit the signals such that during a part of each time interval in the first set of time intervals two polarizations are used for transmission, while during the remaining part of each time interval in the first set of time intervals only one polarization is used for transmission, or b) the transceiver units in the group: i) operate in a FDD mode and not a TDD mode, ii) are arranged to transmit signals using a first set of frequency bands and receive signals using a second set of frequency bands, the first set of frequency bands and the second set of frequency bands being separated from each other, and iii) are arranged to transmit the signals such that for a part of each set of frequency bands two polarizations are used for transmission, while for the remaining part of each set of frequency bands only one polarization is used for transmission.

2. The group according to claim 1 , wherein the transceiver units are arranged for transmitting the signals by means of two polarizations during certain time periods or frequency intervals, and by means of one polarization during other time periods or frequency intervals.

3. The group according to claim 1 , wherein each transceiver unit in the group comprises a double-polarized antenna arranged for both transmission and reception.

4. The group according to claim 1 , wherein each transceiver unit in the group comprises a single-polarized antenna function arranged for both transmission and reception, each single-polarized antenna function having vertical and horizontal polarization components of equal amplitude, such that any transceiver unit in the group has a polarization for reception that is essentially orthogonal to the polarization of a signal transmitted from any other transceiver unit in the group.

5. The group according to claim 1 , wherein the transceiver units in the group comprise transceiver units in the form of base stations.

6. The group according to claim 1 , wherein the transceiver units in the group comprise transceiver units in the form of laptops and/or cell phones.

7. The group according to claim 1 , wherein a node is arranged to control the transmitting polarization of the transceiver units.

8. A method in a group of at least two transceiver units in at least one wireless communication system, the method comprising the steps of: using the transceiver units in the group for wireless communication with at least one other transceiver unit; and controlling the transceiver units in the group to transmit signals using polarizations that are essentially parallel to each other when received by at least one transceiver unit for which the transmitted signals constitute interference; where the essentially parallel polarizations are orthogonal to a polarization for reception when received by said at least one transceiver unit for which the transmitted signals constitute interference, wherein a) the transceiver units in the group: i) operate in a Time Division Duplex (TDD) mode and not a Frequency Division Duplex (FDD) mode, ii) are arranged to transmit signals during a first set of time intervals and receive signals during a second set of time intervals, the first set of time intervals and the second set of time intervals being separated from each other, and iii) are arranged to transmit the signals such that during a part of each time interval in the first set of time intervals two polarizations are used for transmission, while during the remaining part of each time interval in the first set of time intervals only one polarization is used for transmission, or b) the transceiver units in the group: i) operate in a FDD mode and not a TDD mode, ii) are arranged to transmit signals using a first set of frequency bands and receive signals using a second set of frequency bands, the first set of frequency bands and the second set of frequency bands being separated from each other, and iii) are arranged to transmit the signals such that for a part of each set of frequency bands two polarizations are used for transmission, while for the remaining part of each set of frequency bands only one polarization is used for transmission.

9. The method according to claim 8 , wherein the transceiver units are arranged for transmitting the signals by means of two polarizations during certain time periods or frequency intervals, and by means of one polarization during other time periods or frequency intervals.

10. The method according to claim 8 , wherein each transceiver unit in the group uses a double-polarized antenna arranged for both transmission and reception.

11. The method according to claim 8 , wherein each transceiver unit in the group uses a single polarized antenna function arranged for both transmission and reception, each single-polarized antenna function having vertical and horizontal polarization components of equal amplitude such that any transceiver unit in the group uses a polarization for reception that is essentially orthogonal to the polarization of a signal transmitted from any other transceiver unit in the group.

12. The method according to claim 8 , wherein the method is used in a cellular communication system.

13. The method according to claim 8 , wherein a node is arranged to control the transmitting polarization of the transceiver units.

14. The method according to claim 8 , wherein each of the transceiver units in the group: i) operate in a TDD mode and not an FDD mode, ii) are arranged to transmit signals during a first set of time intervals and receive signals during a second set of time intervals, the first set of time intervals and the second set of time intervals being separated from each other, and iii) are arranged to transmit signals such that during a part of each time interval in the first set of time intervals two polarizations are used for transmission, while during the remaining part of each time interval only one polarization is used for transmission.

15. The group according to claim 1 , wherein each of the transceiver units in the group: i) operate in a TDD mode and not an FDD mode, ii) are arranged to transmit signals during a first set of time intervals and receive signals during a second set of time intervals, the first set of time intervals and the second set of time intervals being separated from each other, and iii) are arranged to transmit signals such that during a part of each time interval in the first set of time intervals two polarizations are used for transmission, while during the remaining part of each time interval only one polarization is used for transmission.